# Start, pause & finish

URL: https://docs.ablyft.com/guides/experiments/start-pause-stop/

> The experiment lifecycle in ABlyft, from draft to running, paused and archived.



Every experiment has a **status** that tells you whether visitors can see it. You change the status yourself, or let a
[schedule](https://docs.ablyft.com/guides/experiments/scheduling/) do it. This page explains the four statuses, how to switch between them and
how to finish an experiment.

## The statuses

| Status      | What it means                                                                                                         |
| ----------- | --------------------------------------------------------------------------------------------------------------------- |
| **Draft**   | The experiment is being built. It is not part of your snippet, so nobody sees it. A new experiment starts as a draft. |
| **Preview** | You and your colleagues can check the experiment with a preview link. Normal visitors do not see it.                  |
| **Running** | The experiment is live. Eligible visitors are assigned to a variation and data is collected.                          |
| **Paused**  | The experiment is no longer delivered. Visitors see your original page again.                                         |

The current status is shown at the top of the experiment, in the menu button **Experiment is in draft**, **Experiment is
in preview**, **Experiment is running** or **Experiment is paused**. In the experiment list, you can filter by status and
the list is sorted with running experiments first.

> **There is no Stop button:** ABlyft has no separate "Stop" status. To end an experiment, **pause** it. When you no longer need it, **archive** it
> (see [Finish an experiment](#finish-an-experiment)).

## Before you can preview or start

An experiment needs at least **one variation, one page and one goal**. Otherwise ABlyft shows the message
**Experiment cannot be started** (or **Experiment cannot be set to preview**) and lists what is missing, for example
"Provide at least one page and goal".

If you are not sure how to set up these building blocks, see
[Your first experiment](https://docs.ablyft.com/guides/getting-started/first-experiment/).

## Change the status

Open the experiment. You can change the status in two places:

* The buttons next to the status menu: **Start**, **Pause** and **Preview mode**. Only the actions that make sense for
  the current status are shown.
* The status menu itself (**Experiment is …**), which also contains **Set back to draft**.

Every change asks for a confirmation.

| Action                                            | Available when           | Result                                             |
| ------------------------------------------------- | ------------------------ | -------------------------------------------------- |
| **Preview mode**                                  | Draft, running, paused   | The experiment becomes available for preview only. |
| **Start**                                         | Draft, preview, paused   | The experiment goes live.                          |
| **Pause** (also **Pause experiment** in the menu) | Running                  | The experiment is no longer delivered.             |
| **Set back to draft**                             | Preview, running, paused | The experiment returns to draft.                   |

You need the role **member**, **admin** or **owner** to change the status. **Viewers** can only look. See
[Roles & permissions](https://docs.ablyft.com/guides/projects-and-teams/roles-and-permissions/).

> **Starting a paused experiment continues it:** **Start** on a paused experiment makes it live again. It does not create a new experiment. If you want to begin with
> fresh data, [clone](https://docs.ablyft.com/guides/experiments/clone-and-archive/) the experiment instead.

### Preview

Use the preview status to check your variations, targeting and goals before real visitors see anything. The experiment
page then shows a **Preview** box with the preview links. How to use it is explained in
[Preview & QA](https://docs.ablyft.com/guides/experiments/preview-and-qa/).

### Start

1. Open the experiment and click **Start**.
2. Confirm.
3. The status changes to **Running** and ABlyft publishes your changes.

Once the experiment has been started, a **Results** button appears at the top of the experiment.

### Pause

Click **Pause** and confirm. The experiment is removed from your snippet and visitors see the original page. The
results you collected so far stay available.

You can also pause several experiments at once in the experiment list: select them, open the bulk actions and choose
**Pause selected**. In the row menu of an experiment, **Pause** is also available.

### Set back to draft

**Set back to draft** moves the experiment to the draft status. Use it if you want to rebuild an experiment that is in
preview or paused. If the experiment was active (running or in preview), ABlyft publishes the change.

## Publishing delay

When you start, pause or otherwise change a live experiment, ABlyft publishes a new version of your snippet. In the top
bar, the indicator **Publishing …** with a countdown shows how long this takes. The delay exists because visitors'
browsers may keep using a cached copy of the snippet.

Until the countdown has finished, some visitors can still see the previous state. The cache time is set in the
[snippet settings](https://docs.ablyft.com/developers/installation/snippet-settings/#cache-expiration-ttl).

## Finish an experiment

When you have enough data:

1. **Pause** the experiment so that visitors see the original page again.
2. Look at the [results](https://docs.ablyft.com/guides/results/interpret-results/).
3. **Archive** the experiment when you no longer need it in the list. See
   [Clone & archive](https://docs.ablyft.com/guides/experiments/clone-and-archive/).

If you want ABlyft to end experiments for you, there are two options:

* A [schedule](https://docs.ablyft.com/guides/experiments/scheduling/) pauses the experiment at a given date, after a number of participants
  or after a number of days.
* The project setting **Auto-pause on significance** pauses a running experiment automatically, see
  [Primary and secondary goals](https://docs.ablyft.com/guides/goals-and-measurement/configure-goals/#primary-and-secondary-goals).

## Next steps

- [Scheduling](https://docs.ablyft.com/guides/experiments/scheduling/): Start and pause automatically.
- [Preview & QA](https://docs.ablyft.com/guides/experiments/preview-and-qa/): Check an experiment before it goes live.
- [Clone & archive](https://docs.ablyft.com/guides/experiments/clone-and-archive/): Reuse and tidy up experiments.